Using ozone in a recirculating aquaculture system for Atlantic halibut (Hippoglossus hippoglossus): Water quality, toxicity, and economic considerations

Ozone is a powerful oxidant and is becoming popular in aquaculture systems for disinfection and improving water quality. However, the use of ozone in land-based, recirculating aquaculture systems (RAS) has been limited because of the lack of design and performance information. This study investigated three key issues regarding the use of ozone in a RAS: water quality, toxicity, and economics. Thus, the study design was three-fold. First, water quality monitoring was conducted at the study site to compare two ozonated modules and one control module. Secondly, a risk quotient profile for ozone decomposition was developed to determine the risk to the cultured species. Feed and biomass data were also analysed. Thirdly, the capital and operating costs of installing an ozone system into a RAS were examined. This study found that there are potential benefits if ozone treatment is integrated into a land-based RAS, and the costs are marginal.